采用造粒原料燃烧合成Si_3N_4粉体

Combustion Synthesis of Si_3N_4 Powder Using Pelletized Starting Materials

通过将Si/Si_3N_4原料造粒,采用燃烧合成工艺在较低氮气压力下(2.0 MPa)合成了Si_3N_4粉体。研究了原料造粒对原料孔隙率及燃烧合成反应过程的影响。实验结果表明:原料造粒后燃烧合成通过两步反应完成,通过调整DS/DL(造粒原料最小粒径与最大粒径的比值)可以控制原料坯体的孔隙率和燃烧合成温度及速度,进而提高装料量及氮化率。

Si_3N_4powder was fabricated by combustion synthesis using pelletized Si/Si_3N_4 reactant under a relatively low N2 pressure of 2.0 MPa.Relations between raw pellet sizes with porosity of green body and processing parameters of combustion synthesis were studied.The results indicate that the combustion mode using palletized materials is a two-step reaction.The porosity of reactant compacts,combustion temperature and propagation velocity of combustion waves can be controlled by DS/DL,which can improve the loading and nitriding rate of combustion synthesis.